The present invention relates to a device for monitoring the synchronism of one or more flaps of aircraft wings, wherein the device includes a control cable which is connected with the flaps such that the control cable follows the flap movement.
For influencing the lift and the drag coefficient of the aircraft wings, airplanes are equipped with various flaps which change the aerodynamic properties of the aircraft wings in the desired way. In accordance with the present application, the term “flap” is meant to include any such component which is movable with respect to fixed structural components of the aircraft wing and with which aerodynamic properties can be influenced. Examples include leading-edge flaps and landing flaps.
It is desired, for instance, that for take-off and landing the aircraft has slow flight properties, whereas in cruise flight the leading-edge flaps and landing flaps must be positioned such that fast flight properties can be realized. During operation, the undesired case may happen that malfunctions in the drive system of the flaps occur, which depending on the kind of malfunction can lead to skewing, misalignment or even the loss of individual flaps or flap segments. This involves the disadvantage that the aerodynamic properties of the wings are impaired in an undesired way, for instance by rolling moments or also by consequential damages upon loss of the flaps.
To be able to detect such undesired conditions in time, it is known to monitor the synchronism of flaps of a high-lift system by a control cable mechanism. Such systems are known from U.S. Pat. No. 5,680,124 and EP 0 726 201 A1. In the systems known from these references, the cable ends of the control cable abut against the movable flaps to be monitored. In the case of a malfunction during the movement of one or more flaps, the distance between these stop points is increased, which can be detected by a suitable sensor system. One disadvantage in the system known from the prior art consists in that due to the arrangement of the control cable stop points on the flaps the entire sensor mechanism must follow the movement of the flaps. Another disadvantage consists in that in the systems known from the prior art it is merely possible to detect malfunctions of the movement of two adjacent flaps of an aircraft wing. The known system cannot be used, if only one flap per wing is present or must be monitored.
Finally, it must be regarded as disadvantageous that the drive mechanisms at the outer and inner flap ends, i.e. the outermost and innermost drive mechanisms, cannot be monitored by the known system, as the control cable does not extend up to the vicinity of the same.